As is generally well recognized in the railway industry, prior to the present invention, the throttle controller assemblies which are used in a railway type locomotive are almost exclusively mechanical type throttle controllers. Such mechanical type throttle controller assemblies normally utilize a number of mechanical devices in order to achieve actuation of the necessary microswitches and/or contacts. It is quite well known, for example, that cams are used extensively in this application in order to achieve the required actuation of the various microswitches and/or contacts present in the mechanical type throttle controller.
The mechanical type throttle controllers, presently in use on railway locomotives, have a number of relatively serious drawbacks and/or limitations. These limitations have become more pronounced as the length of freight trains has grown in modern railroading, because the use of more and more locomotives are now required in a train consist in order to pull and/or push the added loads being hauled. For example, these mechanical type throttle controllers utilize either microswitches or contacts to control the voltage that is being applied to the trainline. Furthermore, there is no provision in these prior art mechanical throttle controllers for possible shut down of the system in the event of an output over current.
Additionally, these mechanical type throttle controllers are not equipped to provide the operator of the locomotive with any important feedback information and, consequently, they may not recognize a potential failure situation. Throttle controllers of the mechanical type also utilize either a resistive type voltage divider or a high power potentiometer in order to control the voltage and they are not equipped for shutdown of voltage regulation.
The prior art mechanical throttle controllers provide labels over the mechanical handles to convey only the position of the handle to the locomotive operator. However, these mechanical throttle controllers are not equipped to display certain other relevant information such as various diagnostic information, status information and/or warning type messages.
Furthermore, in a situation where it is either desirable or necessary to provide the required throttle control from a remote host over the communication lines, the currently used mechanical type throttle controllers require that a number of additional relays be used.
It can be seen from the above discussion of the mechanical type throttle controller assemblies presently used in the railroad industry that there is an unfilled need which exists in the railroad industry for an improved railway locomotive type throttle controller assembly which will provide both enhanced performance capability, additional functions which are not possible to accomplish with the prior art mechanical type throttle controllers and more consistent reliability.